Treatment of papulopustular rosacea with ivermectin

ABSTRACT

Methods and compositions for safe and effective treatment of papulopustular rosacea in a subject are described. The methods involve topically applying to an affected skin area a topical composition containing ivermectin and a pharmaceutically acceptable carrier. Treatment with ivermectin represents an innovative therapy that is more robust and effective than the conventional treatments.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is entitled to priority pursuant to 35 U.S.C. §119(e)to U.S. Provisional Patent Application No. 61/843,540, filed Jul. 8,2013, U.S. Provisional Patent Application No. 61/919,208 filed Dec. 20,2013, and U.S. Provisional Patent Application No. 61/927,717, filed Jan.15, 2014, the disclosure of each of which is hereby incorporated byreference herein in its entirety.

BACKGROUND OF THE INVENTION

Papulopustular rosacea (PPR) is a chronic inflammatory disordercharacterized by facial papules, pustules, and persistent erythema.¹ Itis highly prevalent and associated with adverse impact on quality oflife and depression.² The etiology of rosacea is multifactorial. Inaddition to neurovascular dysregulation, the facial skin of patientswith rosacea is affected by augmented proinflammatory immune responses.³The principal active cathelicidin peptide (LL-37) is highly concentratedin skin affected by rosacea and can contribute to acute inflammation.⁴Moreover, PPR is characterized by the presence of inflammatoryinfiltrates that accompany flares, along with a heightened immuneresponse involving neutrophilic infiltration and increased geneexpression of IL-8.⁵ In addition to exogenous factors (including UVlight, heat and alcohol), it may be triggered by Demodex folliculorummites.³ Some studies of PPR observed higher mite densities compared tocontrols.⁶⁻⁷ Therefore, a multitude of factors can activateneurovascular and/or immune responses, and consequential inflammationleading to flares of rosacea.³

Inflammatory lesions of rosacea, particularly moderate to severe PPR,are difficult to treat. Only a few therapeutic alternatives currentlyexist in the treatment of inflammatory lesions of rosacea. In the UnitedStates, only three FDA-approved treatments are indicated for thereduction of inflammatory lesions of rosacea, including two topicaltreatments. A recent Cochrane review noted some evidence supporting theeffectiveness of topical metronidazole and azelaic acid in the treatmentof moderate to severe rosacea,⁸ yet it is clear that not all patientsrespond to these medications. In a national survey of current rosaceamedication users, 46% of patients had previously changed medications,usually due to a lack of improvement.⁹

Ivermectin is an anti-parasitic drug derivative from the macrocycliclactones family approved for human use for treatment andchemoprophylaxis of onchocerciasis and strongyloidiasis since 1996 inthe USA and since 1988 in France. In addition, it has been approved inFrance for the treatment of human scabies. Oral ivermectin in human andanimal demodicidosis was effective in reducing Demodex folliculorum andimproving demodicidosis. Moreover, when administered orally, ivermectincombined with a subsequent weekly application of topical permethrinshowed treatment efficacy in a patient presenting chronic rosacea-likedemodicidosis (14).

U.S. Pat. No. 5,952,372 discloses a method of treating rosacea in humansinvolving orally or topically administering ivermectin. However,according to U.S. Pat. No. 5,952,372, because of the skin barriereffect, topical treatment with ivermectin would be anticipated torequire once- or twice-daily applications for as long as four weeks toachieve sufficient follicle penetration and effective miticidalactivity. It further describes that after ivermectin carries out itsmiticidal activity on skin Demodex folliculorum organisms, inflammatoryresponses to them begin to diminish but remnants of the dead mites stillelicit some flushing and lesion formation until the cleanup processes ofthe body remove them, a process that requires six to eight weeks. Itsuggests to employ conventional anti-rosacea medications, such as oraltetracycline and topical metronidazole, to suppress early flareups andto give early clinical response during the initial phase of ivermectinadministration. U.S. Pat. No. 5,952,372 contains no specific disclosureon topical treatment of PPR.

U.S. Pat. No. 6,133,310 and U.S. Pat. No. 8,415,311 also disclose amethod of treating acne rosacea by topical application of ivermectin.However, they contain no specific disclosure on treating inflammatorylesions of rosacea or PPR.

Accordingly, treatments demonstrated to have a greater efficacy intreating PPR, particularly moderate to severe PPR, than the currentlyavailable compositions, such as metronidazole compositions, are stillneeded to provide greater, longer lasting, or more rapid relief to thosein need of the treatment. There is a need for improved effectivetreatment of PPR, particularly moderate to severe PPR. Such need is metby the present invention.

BRIEF SUMMARY OF THE INVENTION

It is now demonstrated that topical administration of ivermectinprovided more rapid relief of papulopustular rosacea as well as longerperiod of time that is free of relapse as compared to the currentlyavailable treatments, such as the topical treatment with 0.75% by weightof metronidazole.

In one general aspect, embodiments of the present invention relate to amethod of treating papulopustular rosacea in a subject in need thereof,comprising topically administering to a skin area affected by thepapulopustular rosacea a therapeutically effective amount of apharmaceutical composition comprising ivermectin and a pharmaceuticallyacceptable carrier.

Another general aspect of the present invention relates to a method oftreating inflammatory lesions of papulopustular rosacea in a subject inneed thereof, comprising topically administering to a skin area affectedby the inflammatory lesions of papulopustular rosacea a pharmaceuticalcomposition comprising ivermectin and a pharmaceutically acceptablecarrier. In a preferred embodiment of the present invention, thepharmaceutical composition comprises about 0.5% to 1.5% by weightivermectin.

In another preferred embodiment of the present invention, the subjecthas moderate to severe papulopustular rosacea before the treatment.

In yet another preferred embodiment of the present invention, thesubject has at least 10, preferably at least 12 and more preferably atleast 15, inflammatory lesions of papulopustular rosacea, before thetreatment.

According to embodiments of the present invention, once daily topicaltreatment with ivermectin is significantly superior than twice-dailytopical treatment with metronidazole in treating papulopustular rosacea.

Other aspects, features and advantages of the invention will be apparentfrom the following disclosure, including the detailed description of theinvention and its preferred embodiments and the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe invention, will be better understood when read in conjunction withthe appended drawings. For the purpose of illustrating the invention,there are shown in the drawings embodiments which are presentlypreferred. It should be understood, however, that the invention is notlimited to the precise embodiments shown in the drawings.

FIG. 1 shows the median percentage change from baseline in lesion counts(ITT-LOCF population) in a dose range study, after various topicaltreatments;

FIG. 2 illustrates subjects' response to the statement “the productimproves my rosacea” after various topical treatments (ITT Observed);

FIG. 3 shows subject disposition in 2 clinical studies on the safety andefficacy of ivermectin topical treatment;

FIG. 4 illustrates proportions of subjects achieving IGA success(“clear” or “almost clear”): (A) at week 12 in studies 1 and 2; (B) atweeks 2, 4, 8 and 12 in study 1; and (C)) at weeks 2, 4, 8 and 12 instudy 2, wherein SOOLANTRA is a 1% ivermectin cream;

FIG. 5 shows the change from baseline in inflammatory lesion counts(ITT-LOCF): (A) mean absolute change (±standard error) in study 1; (B)mean absolute change (±standard error) in study 2; (C) median percentchange in study 1; and (D) median percent change in study 2, whereinSOOLANTRA is a 1% ivermectin cream;

FIG. 6 show subjects' rating of rosacea improvement in (A) Study 1 and(B) Study 2 at week 12;

FIG. 7 are photographs of a patient at Baseline and Week 12 (standardlight);

FIG. 8 shows subject disposition in a clinical study comparing thetopical treatments with ivermectin and metronidazole;

FIG. 9 illustrates the mean percent change from baseline in inflammatorylesion counts (ITT-LOCF) after the topical treatments with ivermectinand metronidazole, *p<0.05, **p<0.001;

FIG. 10 shows the success rate based on IGA of “clear” or “almost clear”after the topical treatments with ivermectin and metronidazole, *p<0.05, ** p<0.001;

FIG. 11 shows subjects' rating of rosacea improvement after the topicaltreatments with ivermectin and metronidazole; and

FIG. 12 shows time to first relapse defined as first re-occurrence ofIGA≧2 after the successful treatments with ivermectin and metronidazole.

DETAILED DESCRIPTION OF THE INVENTION

Various publications, articles and patents are cited or described in thebackground and throughout the specification; each of these references isherein incorporated by reference in its entirety. Discussion ofdocuments, acts, materials, devices, articles, or the like which havebeen included in the present specification is for the purpose ofproviding context for the present invention. Such discussion is not anadmission that any or all of these matters form part of the prior artwith respect to any inventions disclosed or claimed.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which this invention pertains. Otherwise, certain terms usedherein have the meanings as set forth in the specification. All patents,published patent applications and publications cited herein areincorporated by reference as if set forth fully herein. It must be notedthat as used herein and in the appended claims, the singular forms “a,”“an,” and “the” include plural references unless the context clearlydictates otherwise.

Ivermectin is a member of the avermectin class, which has been shown inimmunopharmacological studies to exert anti-inflammatory effects byinhibiting lipopolysaccharide-induced production of inflammatorycytokines, such as tumor necrosis factor alpha and interleukin (IL)-1b,while upregulating the anti-inflammatory cytokine IL-10¹⁰. It is asemi-synthetic derivative isolated from the fermentation of Streptomycesavermitilis, that belongs to the avermectin family of macrocycliclactones. Ivermectin is a mixture containing5-O-demethyl-22,23-dihydroavermectin Ala plus5-O-demethyl-25-de(1-methylpropyl)-25-(1-methylethyl)-22,23-dihydroavermectinAla, generally referred to as 22,23-dihydroavermectin B1a and B1b orH2B1a and H2B1b, respectively. The respective empirical formulas ofH2B1a and H2B1b are C₄₈H₇₄O₁₄ and C₄₇H₇₂O₁₄ with molecular weights of875.10 and 861.07 respectively.

Ivermectin is a macrocyclic lactone derivative, its therapeutic effectis thought to be prominently due to its anti-inflammatory properties,similar to that of other macrolides.¹¹⁻¹² Avermectin has been reportedto exert anti-inflammatory effects by inhibitinglipopolysaccharide-induced production of inflammatory cytokines. Inaddition to its anti-inflammatory mode of action, ivermectin possessesantiparasitic properties. Its predecessor, avermectin, is anantiparasitic agent of agricultural importance first isolated in 1974.¹³Several studies support ivermectin's role in the effective oraltreatment of cutaneous demodicidosis (in combination with topicalpermethrin cream) and scabies, as well as topical treatment of headlice.¹⁴⁻¹⁶ Ivermectin causes death of parasites, primarily throughbinding selectively and with high affinity to glutamate-gated chloridechannels, which occur in invertebrate nerve and muscle cells. This leadsto the interruption of nerve impulses, causing paralysis and death ofparasitic organisms. Ivermectin is known to act on Demodex mites inlocalized and generalized demodicidosis in animals and in humans.

In the present invention, studies were conducted to evaluate theefficacy and safety of ivermectin in treating papulopustular rosacea(PPR). It was discovered that, as early as 2 weeks after the initialtopical administration of a pharmaceutical composition comprising 0.5 to1.5% (w/w) ivermectin to the subject, a significant reduction ininflammatory lesion count was observed. As used herein, a “significantreduction” refers to a reduction that is statistically significant, notdue to chance alone, which has a p-value of 0.05 or less. A “significantreduction” can have a p-value of less than 0.05, 0.04, 0.03, 0.01,0.005, 0.001, etc. As used herein, “inflammatory lesion count” refers tothe number of inflammatory lesions associated with rosacea or PPR.Inflammatory lesions can be papules and/or pustules. A papule is asmall, solid elevation less than one centimeter in diameter, and apustule is a small, circumscribed elevation of the skin, which containsyellow-white exudates.

The lesions can be, e.g., papules and/or pustules of any sizes (small orlarge). For example, at two weeks after the initial treatment, about 30%(p<0.001) and 27.3% (p<0.01) median reduction of the inflammatory lesioncounts were observed from patients treated with ivermectin in twoseparate clinical studies using methods of the present invention. Thesereductions are statistically significant because they had p values lessthan 0.01 or even less than 0.001.

This early onset of significant effectiveness is unexpected andsurprising in comparison with the conventional treatments. For example,significant treatment differences were only observed from week 4 or week8 forward in two phase III studies for the topical treatment of moderatePPR using twice-daily 15% azelaic acid (Thiboutot et al., 2003, J. AmAcad Dermatol, 48 (6): 836-845), while no statistically significantdifference with respect to the median inflammatory lesion counts or themedian percentage change in inflammatory lesion counts was observed atany evaluation time during the study (P≧0.29) of topical treatment ofmoderate to severe PPR using once-daily 0.75% or 1.0% metronidazole(Dahl et al., 2001, J. Am Acad Dermatol, 45 (5): 723-730).

This early onset of significant effectiveness is also unexpected andsurprising in view of the prior teaching, that topical treatment withivermectin would be anticipated to require once- or twice-dailyapplications for as long as four weeks to achieve sufficient folliclepenetration and effective miticidal activity; and that after ivermectincarries out its miticidal activity on skin Demodex folliculorumorganisms, remnants of the dead mites still elicit some flushing andlesion formation until the cleanup processes of the body remove them, aprocess that requires six to eight weeks; and that conventionalanti-rosacea medications, such as oral tetracycline and topicalmetronidazole, are suggested to be employed to suppress early flareupsand to give early clinical response during the initial phase ofivermectin administration (see, e.g., U.S. Pat. No. 5,952,372).

Side-by-side clinical studies in the present invention also showed thatmethods according to embodiments of the present invention result in moreeffective treatment of PPR as well as longer time for the relapse of PPRto occur than the conventional topical treatment, such as that withmetronidazole. In addition, methods according to embodiments of thepresent invention also result in less frequent adverse skin reactionsthan the conventional topical treatments.

While not wishing to be bound by the theory, it is believed that themechanism of action of ivermectin in treating papulopustular rosacea maybe linked to anti-inflammatory effects of ivermectin as well as thedeath of Demodex mites that have been reported to be a factor ininflammation of the skin. Because ivermectin has both anti-inflammatoryand anti-parasitic activities, treatment of PPR with ivermectinrepresents an innovative therapy addressing these relevant pathogenicfactors in PPR, thus a novel addition to the current treatmentarmamentarium.

According to an embodiment of the present invention, a method oftreating papulopustular rosacea in a subject in need thereof, comprisestopically administering to a skin area affected by the papulopustularrosacea a pharmaceutical composition comprising ivermectin and apharmaceutically acceptable carrier.

As used herein, “pharmaceutically acceptable carrier” refers to apharmaceutically acceptable vehicle or diluent comprising excipients andauxiliaries that facilitate processing of the active compounds intopreparations which can be used pharmaceutically.

The pharmaceutical compositions according to the invention are suitedfor treating the skin. They can be in liquid, pasty or solid form, andmore particularly in the form of ointments, creams, milks, pomades,powders, impregnated pads, syndets, towelettes, solutions, gels, sprays,foams, suspensions, lotions, sticks, shampoos or washing bases. They canalso be in the form of suspensions of microspheres or nanospheres or oflipid or polymeric vesicles or of polymeric patches and of hydrogels forcontrolled release. These compositions for topical application can be inanhydrous form, in aqueous form, or in the form of an emulsion.

In one embodiment of the present invention, the pharmaceuticalcomposition being formulated as an emulsion, the topical pharmaceuticalemulsion comprises ivermectin, and one or more other ingredientsselected from the group consisting of: an oily phase comprisingdimethicone, cyclomethicone, isopropyl palmitate and/or isopropylmyristate, the oily phase further comprising fatty substances selectedfrom the group consisting of cetyl alcohol, cetostearyl alcohol, stearylalcohol, palmitostearic acid, stearic acid and self-emulsifiable wax; atleast one surfactant-emulsifier selected from the group consisting ofglyceryl/PEG100 stearate, sorbitan monostearate, sorbitan palmitate,Steareth-20, Steareth-2, Steareth-21 and Ceteareth-20; a mixture ofsolvents and/or propenetrating agents selected from the group consistingof propylene glycol, oleyl alcohol, phenoxyethanol and glyceryltriacetate; one or more gelling agents selected from the groupconsisting of carbomers, cellulose gelling agents, xanthan gums,aluminum magnesium silicates but excluding aluminum magnesiumsilicate/titanium dioxide/silica, guar gums, polyacrylamides andmodified starches; and water.

In a preferred embodiment of the present invention, the pharmaceuticalcomposition comprises 0.5-1.5% (w/w) ivermectin, more preferably, about1% (w/w) ivermectin, and a pharmaceutically acceptable carrier.

In another preferred embodiment of the present invention, thepharmaceutical composition comprises about 1% (w/w) ivermectin, and oneor more inactive ingredients selected from the group consisting ofcarbomer, such as carbomer copolymer type B; cetyl alcohol; citric acidmonohydrate; dimethicone 20 Cst; edetate disodium; glycerin; isopropylpalmitate; methyl paraben; oleyl alcohol; phenoxyethanol; polyoxyl 20cetostearyl ether; propylene glycol; propyl paraben; purified water;sodium hydroxide; sorbitan monostearate and stearyl alcohol.

As used herein, the term “subject” means any animal, preferably amammal, most preferably a human, to whom will be or has beenadministered compounds or topical formulations according to embodimentsof the invention. Preferably, a subject is in need of, or has been theobject of observation or experiment of, treatment or prevention ofpapulopustular rosacea.

As known to those skilled in the art, an “intent-to-treat population” or“ITT population” refers to all subjects who are randomized in a clinicalstudy and to whom the study drug is administered. “ITT-LOCF” refers tothe ITT population using the Last Observation Carried Forward (LOCF)method, a standard method of handling missing data, which imputes orfills in values based on existing data. “ITT-MI” refers to the ITTpopulation using the multiple imputations (MI) method based on all thedata available in the model, another method for processing data known tothose skilled in the art. A “per protocol population” or “PP population”refers to subjects of the ITT population in a clinical study who have nomajor deviations from the protocol of study.

In one embodiment, “treatment” or “treating” refers to an amelioration,prophylaxis, or reversal of a disease or disorder, or of at least onediscernible symptom thereof. In another embodiment, “treatment” or“treating” refers to an amelioration, prophylaxis, or reversal of atleast one measurable physical parameter related to the disease ordisorder being treated, not necessarily discernible in or by the mammal.In yet another embodiment, “treatment” or “treating” refers toinhibiting or slowing the progression of a disease or disorder, eitherphysically, e.g., stabilization of a discernible symptom,physiologically, e.g., stabilization of a physical parameter, or both.In yet another embodiment, “treatment” or “treating” refers to delayingthe onset of a disease or disorder.

Success of treating PPR can be measured using methods known in the art,such as by the reduction of inflammatory lesion count from the baselinebefore treatment, by an improvement from the baseline in aninvestigator's global assessment (IGA) score, or by both the reductionof inflammatory lesion count and the IGA score.

The IGA score is determined by a trained medical professional evaluatingthe skin condition of a patient utilizing an investigative globalassessment of the skin condition. Typically, such global assessmentsassign a value to the degree of rosacea exhibited by the skin. Inaddition to the assessment made by the medical professional, thepatient's input and observations of their skin condition and responsesto various inquiries (e.g., stinging or burning sensations) also play arole in determining the IGA score that is assigned. For example, the IGAscore for rosacea (Table 1) can range, for example, from 0 (clear) to 1(almost clear) to 2 (mild) to 3 (moderate) to 4 (Severe), includingvalues between these numeric gradings, such as 1.5, 2.6, 3.4 etc. (e.g.,intervals of 0.1).

TABLE 1 Investigator's Global Assessment of Rosacea Severity Grade ScoreClinical Description Clear 0 No inflammatory lesions present, noerythema Almost Clear 1 Very few small papules/pustules, very milderythema present Mild 2 Few small papules/pustules, mild erythemaModerate 3 Several small or large papules/pustules, moderate erythemaSevere 4 Numerous small and/or large papules/pustules, severe erythema

In view of the present disclosure, a skin area that is affected bypapulopustular rosacea can be identified using any diagnostic signs ormeans known in the art, and can be treated by methods according toembodiments of the present invention. Patients can have papulopustularrosacea at different stages, from mild to severe.

In a preferred embodiment, the patient has moderate to severepapulopustular rosacea. As used herein, a patient having “moderate tosevere papulopustular rosacea” has at least moderate facial erythema andat least 10 papulopustular lesions before treatment. For example, thepatient can have an IGA of rosacea of 3 or 4, and at least 10, 15, 20,25 or more papulopustular lesions before treatment.

According to embodiments of the present invention, the papulopustularrosacea is treated by topically applying to a skin area affected by thepapulopustular rosacea a pharmaceutical composition comprisingivermectin and a pharmaceutically acceptable carrier, and the treatmentresults in a reduction in the inflammatory lesion count from thebaseline number of PPR lesions (before treatment) by at least 1 to 100lesions or more, such as at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30,35, 40, 50, 60, 70, 80, 90 or 100 lesions or more. According toembodiments of the present invention, at least about 10%, 20%, 30%, 40%,50%, 60%, 70%, 80%, 90% or 100% reduction in inflammatory lesion countis observed after the treatment. Depending on the number of inflammatorylesions, and other factors, such as the conditions of the patient, thetreatment can last as long as it is needed, such as 4 to 12 weeks.

According to other embodiments of the present invention, the treatmentreduces the IGA score in the treated subject. As used herein, the“success rate” in a clinical study refers to the percentage of subjectsin the study having an IGA of 0 (“clear”) or 1 (“almost clear”) afterthe treatment.

According to embodiments of the present invention, the pharmaceuticalcomposition can be topically administered once or twice daily,preferably once daily.

According to embodiments of the present invention, after the initialsuccessful treatment with ivermectin, i.e., to an IGA of 0 or 1, ittakes a longer time to relapse, i.e., to an IGA of 2 or above, ascompared to the conventional treatments, such as topical treatment with0.75% by weight metronidazole. For example, treatment with ivermectin(1%) once daily (QD) resulted in a statistically significant extendedremission (e.g., delayed time to first relapse, and increase in thenumber of treatment free days) of rosacea when compared to metronidazole0.75% BID in subjects who were successfully treated (IGA 0 or 1) for 16weeks. There was also a numerical trend in favor of ivermectin 1% QD forthe relapse rates.

As used herein, “time to first relapse” is defined as the time elapsedbetween initial successful treatment to an IGA of rosacea of 0 or 1 tothe first reoccurrence of the IGA to 2 or more in a subject. Accordingto embodiments of the present invention, the median time to firstrelapse is about 110, 115, 120, 125, 130, 135, 140, 145 or 150 days ormore in subjects treated with ivermectin, with a p value of 0.05 orless.

Another aspect of the present invention relates to a method of treatinginflammatory lesions of papulopustular rosacea in a subject in needthereof, comprising topically administering to a skin area affected bythe inflammatory lesions of papulopustular rosacea a pharmaceuticalcomposition comprising ivermectin and a pharmaceutically acceptablecarrier.

Preferably the subject has moderate to severe PPR before the treatment.More preferably, the subject has at least 15 inflammatory lesions of PPRbefore the treatment.

In another preferred embodiment, at two weeks after the initialtreatment, about 27% or more median reduction of the inflammatory lesioncounts is observed from subjects treated with ivermectin, with a p valueof 0.01 or less.

Preferably, the pharmaceutical composition comprises 0.5% to 1.5% byweight ivermectin, more preferably about 1% by weight ivermectin.

In an embodiment of the present invention, as early as 2 weeks after theinitial administration of the pharmaceutical composition to the subject,significant reduction in the inflammatory lesion count in the subject isobserved. In other embodiments of the present invention, the methodresults in more reduction of the inflammatory lesion count and longerrelapse-free time of the inflammatory lesions of rosacea in the subjectin comparison to that achieved by topically administering to the subjecta second pharmaceutical composition comprising 0.75% by weightmetronidazole.

This invention will be better understood by reference to thenon-limiting examples that follow, but those skilled in the art willreadily appreciate that the examples are only illustrative of theinvention and the claims which follow thereafter.

Unless otherwise indicated, all percentages of the ingredients in thepresent application are percentages by weight (w/w).

Example 1 Topical Ivermectin Compositions

Examples of pharmaceutical compositions that can be used in the presentinvention are described in U.S. Pat. No. 8,415,311 and U.S. Pat. No.8,470,788, which are incorporated herein by reference. Compositionsuseful in the present invention include, but are not limited to, thefollowing:

Composition 1

% by weight relative to the total weight of the Ingredients CompositionIvermectin 1.00 Glycerol 4.0 Aluminum magnesium silicate 1.0 Methylpara-hydroxybenzoate 0.2 Disodium EDTA 0.05 Citric acid monohydrate 0.05Isopropyl palmitate 4.0 Glyceryl/PEG 100 stearate 3.0 Self-emulsifiablewax 2.0 Palmitostearic acid 2.5 Steareth-20 3.0 Sorbitan stearate 2.0Dimethicone 20 0.5 Propyl para-hydroxybenzoate 0.1 Propylene glycol 4.0Glyceryl triacetate 1.0 Phenoxyethanol 0.5 10% sodium hydroxide qs pHWater qs 100

Composition 2

% by weight relative to the total weight of the Ingredients CompositionIvermectin 1.00 Glycerol 4.0 Acrylate C10-30 alkyl acrylate 0.15Crosspolymer Methyl para-hydroxybenzoate 0.2 Disodium EDTA 0.05 Citricacid monohydrate 0.05 Isopropyl myristate 4.0 Cetyl alcohol 3.0 Stearylalcohol 2.0 Self-emulsifiable wax 0.8 Palmitostearic acid 0.5Steareth-20 2.0 Sorbitan palmitate 1.0 Dimethicone 20 0.5 Propylpara-hydroxybenzoate 0.1 Propylene glycol 4.0 Glyceryl triacetate 1.0Phenoxyethanol 0.5 10% sodium hydroxide qs pH Water qs 100

Composition 3

% by weight relative to the total weight of the Ingredients CompositionIvermectin 1.00 Glycerol 4.0 Aluminum magnesium 1.0 silicate Methylpara- 0.2 hydroxybenzoate Disodium EDTA 0.05 Citric acid 0.05monohydrate Isopropyl palmitate 4.0 Glyceryl/PEG 100 3.0 stearateSelf-emulsifiable wax 2.0 Palmitostearic acid 3.0 Steareth-20 3.0Sorbitan palmitate 2.0 Dimethicone 20 0.5 Propyl para- 0.1hydroxybenzoate Propylene glycol 4.0 Glyceryl triacetate 1.0Phenoxyethanol 0.5 10% sodium hydroxide qs pH Water qs 100

Composition 4

% by weight relative to the total weight of the Ingredients CompositionIvermectin 1.00 Glycerol 4.0 Acrylate C10-30 alkyl acrylate 0.2Crosspolymer Methyl para-hydroxybenzoate 0.2 Disodium EDTA 0.05 Citricacid monohydrate 0.05 Isopropyl palmitate 4.0 Cetyl alcohol 3.5 Stearylalcohol 2.5 Oleyl alcohol 2.0 Ceteareth-20 3.0 Sorbitan monostearate 2.0Dimethicone 200 20 cs 0.5 Propyl para-hydroxybenzoate 0.1 Propyleneglycol 2.0 Phenoxyethanol 1.0 10% sodium hydroxide qs pH Water qs 100

Composition 5

% by weight relative to the total weight of the Ingredients CompositionIvermectin 1.4 Glycerol 4.0 Acrylate C10-30 alkyl acrylate 0.2Crosspolymer Methyl para-hydroxybenzoate 0.2 Disodium EDTA 0.05 Citricacid monohydrate 0.05 Isopropyl palmitate 4.0 Cetyl alcohol 3.5 Stearylalcohol 2.5 Oleyl alcohol 2.0 Ceteareth-20 3.0 Sorbitan monostearate 2.0Dimethicone 200 20 cs 0.5 Propyl para-hydroxybenzoate 0.1 Propyleneglycol 2.0 Phenoxyethanol 1.0 10% sodium hydroxide qs pH Water qs 100

Example 2 Dosage Study on Topical Treatment of PPR with Ivermectin

A phase II, randomized, investigator-blinded, parallel-group, active-and vehicle-controlled study was conducted to determine the optimalconcentration and dose regimen of topical ivermectin cream for thetreatment of inflammatory lesions of rosacea, and evaluate efficacy andsafety.

Eligible subjects were adults with PPR. The majority of the subjects hadat least 15 facial inflammatory lesions and at least mild facialerythema based on IGA of rosacea severity. Table 2 shows the demographicand baseline clinical characteristics (ITT population) of the subjects:

TABLE 2 Ivermectin Ivermectin Ivermectin Ivermectin MetronidazoleVehicle 1% BID 1% QD 0.3% 0.1% 0.75% BID QD (N = 48) (N = 52) (N = 47)(N = 51) (N = 48) (N = 50) Gender n (%) Female 39 (81.3) 33 (63.5) 29(61.7) 31 (60.8) 34 (70.8) 35 (70.0) Male  9 (18.8) 19 (36.5) 18 (38.3)20 (39.2) 14 (29.2) 15 (30.0) Age, year Mean ± SD 50.9 ± 12.3 50.4 ±14.5 53.4 ± 14.5 52.7 ± 13.8 52.2 ± 15.9 52.2 ± 14.4 Phototype, n (%) I 7 (14.6) 4 (7.7)  6 (12.8) 4 (7.8) 3 (6.3)  7 (14.0) II 28 (58.3) 27(51.9) 20 (42.5) 26 (51.0) 29 (60.4) 28 (56.0) III 12 (25.0) 14 (26.9)17 (36.2) 18 (35.3) 14 (29.2) 15 (30.0) IV 1 (2.1)  7 (13.5) 4 (8.5) 3(5.9) 2 (4.1) 0 Inflammatory lesion, n (%) Mean ± SD 37.3 ± 39.0 35.8 ±18.2 35.1 ± 20.5 31.1 ± 15.0 37.4 ± 23.9 35.8 ± 19.9 Min, max 16, 27016, 93 14, 108 15, 79 15, 153 15, 120 IGA, n (%) 1 = Almost 2 (4.2) 0 1(2.1) 1 (2.0) 1 (2.1) 1 (2.0) Clear 2 = Mild 15 (31.3) 20 (38.5) 15(31.9) 18 (35.3) 18 (37.5) 12 (24.0) 3 = Moderate 28 (58.3) 24 (46.2) 21(44.7) 29 (56.9) 21 (43.8) 28 (56.0) 4 = Severe 3 (6.3)  8 (15.4) 10(21.3) 3 (5.9)  8 (16.7)  9 (18.0)

The subjects were randomized to receive one of the following six (6)regimens for 12 weeks: ivermectin 0.1% (w/w) once-daily (QD), ivermectin0.3% (w/w) QD, ivermectin 1% (w/w) QD, ivermectin 1% (w/w) twice-daily(BID), metronidazole gel 0.75% (w/w) BID, or vehicle QD. The 6 groupswere comparable in terms of demographic and baseline diseasecharacteristics (Table 2): majority were female, Caucasian, with a skinphototype II and a mean age of 51.9±14.2 years. On average, the subjectshad 35.4±23.8 inflammatory lesions, and the majority (51.0%) had an IGAof 3 (moderate).

Inflammatory lesion (sum of papules and pustules) counts, rate ofsuccess [% subjects “clear” or “almost clear” based on Investigator'sGlobal Assessment (IGA), a scale from 0 (clear) to 4 (severe)], erythema[from 0 (none) to 3 (severe)], telangiectasia [from 0 (none) to 3(severe)], adverse events, and satisfaction questionnaire (at the end ofthe study) were determined during the study.

FIG. 1 shows the median percentage change from baseline in lesion counts(ITT-LOCF population).

At week 12, both ivermectin 1% (w/w) QD and BID were significantly moreeffective than vehicle QD in the ITT-LOCF analysis based on thepercentage change from baseline in inflammatory lesion counts (median:−78.3% and −78.9% vs. −60.6%; both p<0.05) (FIG. 1); this was alsoconfirmed in the PP analysis. Although ivermectin 1% (w/w) BID wassignificantly more efficacious than vehicle, its magnitude of effect wasnot greater than ivermectin 1% (w/w) QD. A numeric trend favoringivermectin 1% QD compared with metronidazole 0.75% BID was also observedin terms of median % change from baseline in inflammatory lesion counts[−78.3% vs. −69.2% at Week 12 (ITT-LOCF)]; the sample size was not largeenough to detect differences between these groups.

All ivermectin dose regimens led to a significantly greater success ratethan vehicle (70.8%, 65.4%, 63.8% and 62.7% for ivermectin 1% BID, 1%QD, 0.3% QD and 0.1% QD, respectively, vs. 42.0% for vehicle at Week 12;all p<0.05). Furthermore, the success rate for Metronidazole was 62.5%.No difference was observed in the change in erythema or telangiectasiabetween the active and control groups.

All regimens were safe and well-tolerated, with similarly low incidenceof adverse events. There were no serious related AEs. The majority ofrelated AEs were mild, transient and dermatologic in nature, the mostfrequent for the ivermectin groups being skin discomfort (4 subjects),skin burning sensation (4 subjects), and worsening of rosacea (3subjects).

FIG. 2 illustrates subjects' response to the statement “the productimproves my rosacea” (ITT Observed). With increasing dosage ofivermectin, more subjects agreed with the statement “the productimproves my rosacea” (FIG. 2) and were satisfied with the product (datanot shown). The result was superior in ivermectin 1% QD and BID groupscompared to the metronidazole 0.75% BID group. The majority of subjectsin all Ivermectin groups considered that the product was easy to use (atleast 95.5%), pleasant to use (at least 77.3%), and did not irritate theskin (at least 70.2%).

Topical administration of all tested ivermectin dose regimens (1% BID,1% QD, 0.3% QD and 0.1% QD) led to a significantly greater success ratein treating PPR than vehicle; the result was superior in ivermectin 1%QD and BID groups compared to the metronidazole 0.75% BID group; andonce daily topical administration of 1% (w/w) ivermectin was consideredthe optimal dose regimen, because it was safe, well tolerated, andprovided significantly greater efficacy than vehicle for the treatmentof PPR. Once daily topical administration is further preferred becauseit promotes better patient compliance.

Example 3 Efficacy and Safety Study of Ivermectin 1% Cream

To demonstrate the efficacy and safety of once-daily ivermectin 1% (w/w)cream in subjects with PPR, two identically designed randomized,double-blind, controlled studies were conducted (hereafter designatedStudy 1 and Study 2). Both studies were conducted in accordance with theethical principles of the Declaration of Helsinki and Good ClinicalPractices, and in compliance with local regulatory requirements.

Each study had three parts. In the first part of the study, subjectswith PPR were treated with ivermectin 1% cream (IVM 1%) or vehicle oncedaily at bedtime for 12 weeks. In the second part of the study, subjectsinitially treated with IVM 1% once daily at bedtime continued the sametreatment, while subjects treated with the vehicle once daily switchedto topical treatment with azelaic acid 15% gel twice daily, in themorning and evening. The third part of the study consisted of 4 weekssafety follow-up, without treatment.

Eligible subjects were 18 years or older, with moderate or severepapulopustular rosacea as noted by an IGA of 3 (“several small or largepapules/pustules, moderate erythema”) or 4 (“numerous small and/or largepapules/pustules, severe erythema”), and presenting with 15-70 facialinflammatory lesions (papules and pustules). A total of 683 subjectswith moderate to severe PPR were randomized in Study 1 (IVM 1%: 451,vehicle: 232), and 688 subjects in Study 2 (IVM 1%: 459, vehicle: 229)(FIG. 3).

Eligible subjects received either ivermectin cream 1% cream (once dailyevery day at bedtime) or vehicle cream (once daily every day at bedtime)on the entire face for 12 weeks. They were instructed to apply a thinfilm of cream on the entire face (right and left cheeks, forehead, chinand nose), e.g., in a pea-size amount of the cream, avoiding the upperand lower eyelids, lips, eyes and mouth. Subjects were also instructedto avoid rosacea triggers, such as sudden exposure to heat, certainfoods, and excessive sun exposure. Study visits during the first studywere as follows: screening visits, baseline, weeks 2, 4, 8, and 12 afterthe initial administration.

Efficacy assessments at each visit were the IGA of disease severity, andinflammatory lesion counts (papules and pustules) on each of the fivefacial regions (forehead, chin, nose, right cheek, left cheek). Safetyassessments included adverse events (AEs) throughout the study, localtolerance parameters (stinging/burning, dryness, itching) at each studyvisit evaluated on a 4-point scale [from 0 (none) to 3 (severe)], andlaboratory parameters (hematology and biochemistry) measured before andafter treatment. Other assessments included the subject's evaluation oftheir rosacea improvement at the end of the study (week 12) compared totheir condition at baseline, and two quality of life (QoL)questionnaires [a dermatology-specific instrument, the Dermatology LifeQuality Index (DLQI)], 17 and a rosacea-specific instrument, theRosaQoL™18 completed at baseline and week 12.

The co-primary efficacy endpoints in both studies were the success ratebased on the IGA outcome and absolute change from baseline ininflammatory lesion counts at the end of week 12 of the studies. Thesuccess rate based on IGA score [% of subjects who achieved “clear” or“almost clear” ratings on the IGA scale at week 12 (ITT-LOCF)] wasanalyzed by the Cochran-Mantel-Haenszel (CMH) test stratified byanalysis site, using the general association statistic. The absolutechange in inflammatory lesion counts from baseline to week 12 (ITT-LOCF)was analyzed by analysis of covariance (ANCOVA). Missing data at week 12in the ITT population were imputed by the LOCF approach. Also,sensitivity analyses were conducted to impute missing data in order toassess the robustness of the primary efficacy results. The secondaryefficacy endpoint was percent change in inflammatory lesion counts frombaseline at week 12 (ITT-LOCF). The QoL questionnaires were analyzedusing the Wilcoxon rank sum test, and other variables were descriptivelyanalyzed. High mean scores from the QoL questionnaires indicated a lowquality of life.

In Studies 1 and 2, the vast majority of subjects completed the study(91.4% and 92.6%, respectively). The treatment groups were similar atbaseline in terms of demographics and baseline disease characteristics,with about 31-33 inflammatory lesions on average and the majority havingmoderate rosacea (Table 3). Most subjects were female (68.2% and 66.7%in Studies 1 and 2, respectively) and Caucasian/white (96.2% and 95.3%),with a mean age of 50.4 and 50.2 years, respectively. Additionally,treatment groups were comparable regarding rates/reasons for early studydiscontinuation (FIG. 3).

TABLE 3 Demographic and baseline clinical characteristics (ITTpopulation) Study 1 Study 2 Total Total (n = 683) (n = 688) Age, yearsMean ± SD 50.4 ± 12.09 50.2 ± 12.29 Min, Max 19, 88 18, 89 Gender, n (%)Female 466 (68.2%) 459 (66.7%) Male 217 (31.8%) 229 (33.3%) Race White657 (96.2%) 656 (95.3%) Black or African  9 (1.3%) 10 (1.5%) AmericanAsian  6 (0.9%) 15 (2.2%) Other 11 (1.6%)  7 (1.0%) Inflammatory lesionMean ± SD 30.9 ± 14.33 32.9 ± 13.70 counts IGA 3 = Moderate 560 (82.0%)403 (83.3%) 4 = Severe 123 (18.0%)  81 (16.7%)

The proportion of subjects achieving IGA success (“clear” or “almostclear”) at week 12 for Studies 1 and 2 were 38.4% and 40.1%,respectively for IVM 1% compared to 11.6% and 18.8% for vehicle (bothp<0.001; FIG. 4A). A significant difference between treatment arms inboth studies was observed based on IGA since week 4 (10.9% and 11.8%versus 5.6% and 5.7%, respectively; both p<0.05), and was sustaineduntil Week 12 (FIGS. 4B and 4C).

For inflammatory lesion counts, the mean difference between IVM 1% andvehicle from baseline to week 12 was −8.13 lesions for Study 1 and −8.22for Study 2 (both p<0.001 versus vehicle), with a 95% CI of [−10.12,−6.13] and [−10.18, −6.25], respectively (FIGS. 5A and 5B). A meanreduction of 9 lesion counts was observed at week 2 in both studies whentreated with IVM 1% (FIGS. 5A and 5B). Median reduction from baseline ininflammatory lesion counts for both studies was 76.0% and 75.0%,respectively, versus 50.0% for both vehicle groups at week 12 (p<0.001),with significant difference observed by week 2 at a median reduction of30% and 27.3% (FIGS. 5C and 5D). This significant reduction ininflammatory lesion counts as early as week 2 was exceptional whencompared with similar data from treatment with metronidazole or azelaicacid.

Table 4 summarizes efficacy outcomes of both studies at the end of thefirst part 12 week studies

IVM 1% Vehicle IVM 1% Vehicle (N = 451) (N = 232) (N = 459) (N = 229)IGA Number (%) of Subjects 173 27 184 43 Clear or Almost Clear in (38.4)(11.6) (40.1) (18.8) the IGA at Week 12 Inflammatory Lesions Meaninflammatory 31.0 30.5 33.3 32.2 lesion count at baseline Meaninflammatory 10.6 18.5 11.0 18.8 lesion count at Week 12 Mean AbsoluteChange −20.5 −12.0 −22.2 −13.4 (%) in Inflammatory (−64.9) (−41.6)(−65.7) (−43.4) Lesion Count from Baseline at Week 12

The incidence of AEs was comparable between Studies 1 and 2 (40.5% and36.5% for IVM 1% versus 39.4% and 36.5% for vehicle, respectively).Fewer subjects in IVM 1% groups tended to report related AEs than invehicle groups (4.2% and 2.6% versus 7.8% and 6.5%, respectively), aswell as for related dermatologic AEs (3.5% and 1.5% versus 6.9% and5.7%) and related AEs leading to discontinuation (1.3% and 0.2%, versus1.7% for both vehicle groups). A similarly low proportion of subjectsreported serious AEs for IVM 1% and vehicle groups (0.7% and 1.5% versus0.4% and 1.7%). There were no related serious AEs. The most commonrelated AE in Study 1 was sensation of skin burning: 8 (1.8%) in IVM 1%subjects versus 6 (2.6%) for vehicle. For Study 2, the most commonrelated AEs for IVM 1% were pruritis and dry skin (3 subjects each(0.7%)) compared to 0 and 2 subjects (0.9%) for vehicle, respectively.In addition, laboratory tests did not demonstrate clinically significantabnormalities.

At baseline before treatment application, a large proportion of subjectspresented with local cutaneous symptoms consistent with rosacea,especially mild or moderate dry skin (for Studies 1 and 2, 63.0% and57.0% for IVM 1%, and 59.3% and 60.0% for vehicle, respectively) andmild or moderate itching (57.3% and 49.4% for IVM 1%, and 45.4% and49.1% for vehicle). At week 12 (last available data observed), themajority of subjects had none of the 2 cutaneous symptoms. A trend wasobserved in terms of absence of dryness in 83-86% of IVM 1% subjectsversus 72-76% for vehicle, as well as for absence of itching in 82-85%for IVM 1% versus 70-78% for vehicle.

Improvement after treatment was rated by subjects as “excellent” or“good” by 69% and 66.2% for IVM 1% compared to 38.6% and 34.4% forvehicle (p<0.001), respectively (FIG. 6). “Excellent” improvement wasreported by 34.3% and 32.0% for IVM 1% versus 9.5% and 7.3% for vehicle.

After 12 weeks of treatment, improved QoL scores were observed forsubjects in the IVM 1% compared to vehicle groups. For the DLQI, it isof note that no difference between treatment groups was observed atbaseline. At the end of each study, more subjects in the IVM 1% group(about 53%) than vehicle (about 35%) considered that their disease hadno effect on their overall QoL (p<0.001). For RosaQoL™, improvement inQoL from baseline was higher in both studies for IVM 1% (−0.64±0.7 and−0.60±0.6 versus −0.35±0.5 for both vehicle groups (p<0.001 and p=0.001for Studies 1 and 2, respectively). This result indicates that a higherproportion of subjects felt that their quality of life was notnegatively impacted by rosacea in the group treated with IVM, comparedto the control group treated with vehicle.

IGA was assessed during the second part of the studies (40 weeks). Thepercentages of subjects treated with IVM 1% achieving an IGA score of 0or 1 continued to increase up to week 52, the end of the second part ofthe studies. The success rate (IGA=0 or 1) at week 52 was 71.1% and 76%in studies 1 and 2 respectively. In both studies, the incidences werecomparable in the 2 groups of subjects treated by IVM 1% cream QD andazelaic acid 15% gel BID across the categories of related AEs,dermatologic AEs, serious AEs, related AEs leading to discontinuation,and AEs of special interests. There was no serious related AEs.

In the follow up third part of the studies, subjects treated with IVM 1%cream QD and azelaic acid 15% gel BID during the second part of thestudies were comparable in reporting AEs. No subjects reported relatedserious AEs, related AEs leading to discontinuation.

The most frequent (>0.5% in any arm) AEs were skin disorders, and wereless frequent with IVM 1% cream QD than azelaic acid 15% gel BID in bothstudies.

These two pivotal studies demonstrated the efficacy and safety oftopical ivermectin 1% cream in the treatment of inflammatory lesions ofrosacea with reproducibility. The effect was robust and highlysignificant (p, 0.001) in all primary and secondary endpoints at week 12(ITT-LOCF). Onset of treatment effect was observed at week 4 in eachstudy based on both IGA and lesion counts. Onset of treatment effect wasobserved at week 2 in each study based on lesion counts. The ivermectin1% cream was well tolerated and safe in both studies. No notabledifference was observed between the ivermectin 1% cream QD andcorresponding vehicle and azelaic acid 15% gel BID. The most frequent(>0.5% in any arm) AEs were skin disorders, and were less frequent withIVM 1% cream QD than with the respective comparator. In addition, thecontinued daily application of the Ivermectin 1% Cream QD up to 1 yearis well tolerated, with no unexpected safety findings associated withchronic use.

In conclusion, ivermectin, such as 1% ivermectin cream, was effectiveand safe in treating papulopustular rosacea.

Example 4 Comparison of the Efficacy and Safety of Ivermectin 1% CreamVs. Metronidazole 0.75% Cream

This was an investigator-blinded, randomized, parallel group studycomparing the efficacy and safety of ivermectin (hereafter designatedIVM) 1% (w/w) cream vs. metronidazole 0.75% (w/w) cream with a 16-weekperiod A and a 36-week period B to study recurrence. Study visits duringPeriod A were as follows: a screening visit, and at baseline, weeks 3,6, 9, 12 and 16.

Eligible subjects were 18 years or older, with moderate or severepapulopustular rosacea as noted by an IGA of 3 (“several small or largepapules/pustules, moderate erythema”) or 4 (“numerous small and/or largepapules/pustules, severe erythema”), and presenting with 15-70 facialinflammatory lesions (papules and pustules).

Subjects were randomized in a 1:1 ratio to receive either IVM 1% cream(once daily, QD, at bedtime) or metronidazole 0.75% cream (twice daily,BID, as per labelling at morning and bedtime) for 16 weeks. Study drugswere applied in a thin film on the entire face (right and left cheeks,forehead, chin and nose), avoiding the upper and lower eyelids, lips,eyes and mouth. The subjects were instructed to maintain a consistentlifestyle throughout the study regarding rosacea triggers (i.e. avoidingenvironmental factors, certain foods, and excessive sun exposure).

Efficacy assessments at each visit were inflammatory lesion counts(papules and pustules) counted on five facial regions (forehead, chin,nose, right cheek, left cheek), and the Investigator's Global Assessment(IGA) of disease severity. Safety assessments included adverse events(AEs) throughout the study, local tolerance parameters(stinging/burning, dryness, itching) at each visit evaluated on a4-point scale (from 0 (none) to 3 (severe)), and laboratory parametersmeasured at baseline, weeks 9 and 16. Other assessments included thesubject's evaluation of rosacea improvement compared to their conditionat baseline, and subject's appreciation questionnaire at the end of thestudy (regarding satisfaction with the study drug). Lastly, a quality oflife questionnaire (Dermatology Life Quality Index (DLQI)) was completedat baseline and at the end of the study (week 16).

The ITT population included all subjects who were randomized and to whomthe study drug was administered. The safety population included allsubjects who received the study medication. The primary efficacyendpoint, percent change in inflammatory lesion counts from baseline toweek 16, was analyzed using the CMH test stratified on center, withridit transformation and row mean score difference statistic. Secondaryefficacy endpoints included success rate (percent of subjects with IGArated 0 (“clear”) or 1 (“almost clear”) (analyzed by CMH test stratifiedon center using general association statistic), IGA and absolute changein lesion counts (analyzed using ANCOVA, including treatments andanalysis center as factors, and baseline as covariate). LOCF was theprimary method for imputation of missing data, and multiple imputations(MI) method was used for sensitivity. Other variables were descriptivelyanalyzed.

A total of 1,034 subjects were screened and 962 randomized to receiveIVM 1% cream (n=478) or metronidazole 0.75% cream (n=484); 902 (93.8%)completed the study (FIG. 8). Treatment groups were comparable atbaseline in terms of demographics and baseline disease characteristics,with about 32 inflammatory lesions on average and the majority havingmoderate rosacea (83.3% with an IGA of 3) (Table 5). As expected, thequantity of product applied in the metronidazole group (BIDapplications) was nearly twice as much as the product applied in the IVM1% group (QD), with a mean of 1.31 g vs. 0.72 g, respectively.

TABLE 5 Demographic and baseline clinical characteristics (ITTpopulation) Metronidazole Ivermectin 1% 0.75% Total (n = 478) (n = 484)(n = 962) Age, years Mean ± SD 51.22 ± 13.40 51.87 ± 13.24 51.54 ± 13.32Min, Max 18, 85 18, 90 18, 90 Gender, n (%) Female 311 (65.1%) 316(65.3%) 627 (65.2%) Male 167 (34.9%) 168 (34.7%) 335 (34.8%) Race Asian 3 (0.6%) —  3 (0.3%) White 475 (99.4%)  484 (100.0%) 959 (99.7%) SkinPhototype I 18 (3.8%) 17 (3.5%) 35 (3.6%) II 245 (51.3%) 234 (48.3%) 479(49.8%) III 178 (37.2%) 213 (44.0%) 391 (40.6%) IV 36 (7.5%) 19 (3.9%)55 (5.7%) V  1 (0.2%)  1 (0.2%)  2 (0.2%) Inflammatory lesion Mean ± SD32.87 ± 13.95 32.07 ± 12.75 32.46 ± 13.36 Counts Investigator Global 3 =Moderate 398 (83.3%) 403 (83.3%) 801 (83.3%) Assessment 4 = Severe  80(16.7%)  81 (16.7%) 161 (16.7%)

Regarding the primary endpoint, at week 16 (ITT-LOCF), IVM 1% cream wassignificantly superior to metronidazole 0.75% cream in terms of percentreduction from baseline in inflammatory lesion counts (83.0% vs. 73.7%;p<0.001; FIG. 9). This difference was observed as early as week 3(ITT-LOCF) (as soon as week 6 with ITT-MI), and this continued throughweek 16 (all p-values ≦0.04). It should be noted that in this study,there was no study visit or assessment prior to Week 3, thus thedifferences in treatment could have been observed earlier than week 3 ifthe first study visit was conducted earlier. Similar results were foundfor the IGA success rate (subjects rated “clear” or “almost clear”):84.9% for IVM 1% cream vs. 75.4% for metronidazole 0.75% cream at week16 (ITT-LOCF) (p<0.001). As illustrated in FIG. 10, the difference inIGA was the highest at week 12 (14.9% superior for ivermectin).

About 13% more subjects were rated as “clear” in terms of IGA for IVM 1%than metronidazole 0.75% (34.9% vs. 21.7%, respectively). Furthermore,in a subgroup analysis of success rate according to IGA severity, about20% more subjects with severe rosacea at baseline in the IVM 1% groupachieved success (82.5% vs. 63.0%).

The incidence of adverse events (AEs) was similar between groups (32.4%vs. 33.1% of subjects in the IVM 1% and metronidazole 0.75% groups,respectively), as well as for related AEs (2.3% vs. 3.7%). Furthermore,a comparably low number of subjects experienced a related dermatologicAE (9 subjects (1.9%) in the IVM 1% group and 12 (2.5%) in themetronidazole 0.75% group). The most common related AE was skinirritation (3 subjects (0.6%) vs. 4 subjects (0.8%) for IVM 1% andmetronidazole 0.75%, respectively). Thirteen subjects reported seriousbut unrelated AEs. A total of 3 subjects (0.6%) in the IVM 1% groupexperienced related adverse events leading to discontinuation (due toskin irritation and hypersensitivity), compared to 10 (2.1%) subjects inthe metronidazole 0.75% group (due to skin irritation, allergicdermatitis, aggravation of rosacea, erythema, pruritis, and generaldisorders (hot feeling)).

In terms of local tolerance, the incidence of worsening from baselinewas higher in the metronidazole 0.75% group for stinging/burning (15.5%vs. 11.1%), dryness (12.8% vs. 10.0%), and itching (11.4% vs. 8.8%).Laboratory tests did not demonstrate clinically significantabnormalities.

At the end of period A of this study, the majority (85.5%) of subjectsin the IVM 1% group rated their global improvement as “excellent” or“good” compared to 74.8% in the metronidazole 0.75% group. Furthermore,more subjects receiving IVM 1% reported an “excellent” improvement oftheir rosacea (52.3% vs. 37.0%, respectively; FIG. 11). Regarding thesubject's appreciation questionnaire, more subjects in the IVM 1% groupwere satisfied with the study drug (76.0% vs. 61.3% in the metronidazole0.75% group). In addition, more subjects treated by IVM 1% tended toconsider the product easy to use and that the time needed forapplication was satisfactory, whereas more subjects found metronidazole0.75% to be irritating (data not shown).

At baseline, the mean DLQI scores were similar between groups (6.95 forIVM 1% and 6.05 for metronidazole 0.75%, respectively). Patients treatedwith IVM 1% showed a higher numerical decrease in their DLQI score thanpatients treated with metronidazole 0.75% (−5.18 vs. −3.92; p<0.01),indicating a higher improvement in quality of life. At the end of thestudy, 71% of patients treated with IVM 1% reported no effect at all ontheir quality of life (vs. 64% for metronidazole 0.75%), which meansthat a higher proportion of subjects felt that their quality of life wasnot negatively impacted by rosacea in the group treated with IVM,compared to the group treated with metronidazole. The study drugsdiverged in favor of IVM 1% in the symptoms and feelings sub-scale(level of itching, soreness, pain or stinging: “not at all” for 78.7%vs. 63.0% in the metronidazole 0.75% group; level of embarrassment orself-consciousness: “not at all” for 70.3% vs. 60.1%, respectively).

Topical metronidazole 0.75% (w/w) has been one of the most frequentlyused therapies in the treatment of papulopustular rosacea. In thisstudy, IVM 1% cream was significantly superior to metronidazole 0.75%cream in terms of percent reduction from baseline in inflammatory lesioncounts, with an onset of efficacy (first difference vs. metronidazole0.75%) as early as 3 weeks (or even earlier) that continued through 16weeks. The findings show that ivermectin is more efficacious thanmetronidazole, with a tendency even in patients with higher lesioncounts.

An overall good safety profile was observed for IVM, and it waswell-tolerated in comparison with metronidazole. It is not surprisingthat for both products, patients experienced a similarly low number ofrelated adverse events, particularly since the tolerability ofmetronidazole is known to be satisfactory. Metronidazole's higherincidence of worsening from baseline concerning stinging/burning,dryness, and itching may be attributed to the usual signs and symptomsof rosacea. Nevertheless, this affected the level of quality of life asmeasured by the DLQI, as more patients in the metronidazole groupreported itching, soreness, pain or stinging.

Patient-reported outcomes for IVM 1% cream were consistent with itssuperior efficacy results. More patients using IVM indicated that theproduct was easy to use and that the time needed for application wassatisfactory, implying that the daily application is more convenientthan metronidazole's twice-daily regimen. Related to quality of lifemeasures, fewer patients using IVM considered themselves to beembarrassed or self-conscious. Thus, ivermectin appears to be adapted tothe complex etiology of rosacea, and in the study IVM 1% creamdemonstrated superiority to metronidazole 0.75% cream in terms ofinflammatory lesion reduction. As noted in the afore-mentioned Cochranereview, few robust studies have compared topical metronidazole withanother rosacea treatment and in three identified studies, topicalmetronidazole was either non-significantly different or less effectivethan azelaic acid.⁸ While metronidazole has been used in the past as areasonable treatment for the papulopustular lesions of rosacea, itsefficacy is surpassed by that of ivermectin along with the advantage ofonce-daily dosing.

The relapse among subjects successfully treated at the end of the PeriodA was studied during the treatment free Period B (36 weeks). At the endof Period A, only subjects with an IGA of “0” or “1” (clear or almostclear) were eligible for entering Period B. Then, their study treatmentwas discontinued and the subjects were followed for up to 8 months (36weeks). In case of reoccurrence of an IGA of at least “2” (mild) at anytime during Period B, the subjects were retreated with the sametreatment received during the Period A. The re-treatment was stopped assoon as the IGA was back to “0” or “1” (clear or almost clear). Themaximum duration of re-treatment was 16 consecutive weeks to mimic thePeriod A treatment duration. In order to characterize the relapses, thefollowing parameters were assessed: (1) time of first relapse (timeelapsed between Week 16 and first reoccurrence of IGA at “2”, “3” or “4”inducing a retreatment course), (2) relapse rate (percentage of subjectswith reoccurrence of IGA at “2”, “3” or “4” after a period free of studytreatment) and (3) number of days free of treatment.

At the start of Period B, treatment groups were comparable with respectto the demographic. Of the total 757 subjects included in Period B (399in Ivermectin 1% and 358 in Metronidazole 0.75% groups, respectively),504 (66.6%) were female, 754 (99.6%) were Caucasian and the mean age was51.9 years. In terms of disease characteristics, the means inflammatorylesion counts were similar in both groups (median 2.0). But, theproportion of subjects with an IGA of 0 was higher in Ivermectin groupthan in Metronidazole group (41.6% versus 29.1%) due to the higherefficacy of Ivermectin treatment from Period A.

TABLE 6 End of Period A disease characteristics of subjects enteringPeriod B Metro- Ivermectin nidazole TOTAL Inflammatory N 399 358 757lesion counts Mean 2.58 2.96 2.76 SD 3.20 3.42 3.31 Median 2.00 2.002.00 Min~Max  0~19 0~24 0~24 P25~P75 0~4 0~4  0~4  Investigator N 399358 757 Global 0 = Clear 166 (41.6%) 104 (29.1%) 270 (35.7%) Assessment1 = Almost 233 (58.4%) 254 (70.9%) 487 (64.3%) Clear Nodules N 399 358757 0 397 (99.5%) 357 (99.7%) 754 (99.6%) 1  2 (0.5%)  1 (0.3%)  3(0.4%) Papules N 399 358 757 Mean 2.27 2.56 2.40 SD 2.77 2.83 2.80Median 2.00 2.00 2.00 Min~Max  0~16 0~17 0~17 P25~P75 0~4 0~4  0~4 Pustules N 399 358 757 Mean 0.32 0.40 0.36 SD 0.91 1.20 1.06 Median 0.000.00 0.00 Min~Max 0~9 0~12 0~12 P25~P75 0~0 0~0  0~0 

The time to first relapse, defined as time elapsed between Week 16 andfirst reoccurrence of IGA at “2”, “3” or“4” was analyzed following 2definitions: (1) the first one was based on IGA only; and (2) the secondone took also into account any major deviations by imputing relapse theday of first major deviation. For each definition, a sensitivityanalysis was performed by imputing relapse 4 weeks after discontinuationfor all subjects who discontinued early from Period B without relapse.Relapse rates followed the same convention analyses as the time torelapse.

The median times to first relapse were 115 days for ivermectin 1% QD and85 days for Metronidazole 0.75% BID (p=0.0365), the relapse rates were62.7% and 68.4% respectively (Table 7). See also FIG. 12. Whenconducting the sensitivity analysis by imputing relapse 4 weeks later tosubjects who discontinued early without relapse, the medians were 114days and 85 days (p=0.0594) and the relapse rates were 66.2% and 70.4%,respectively. Similar results were obtained when taking also intoaccount the day of first major deviation.

TABLE 7 IVM 1% Metronidazole p-value (1) N 399 358 0.0365 Median and 95%115.0 [113; 165] 85.0 [85; 113] — Confidence Interval Mean ± StandardError 147.0 ± 4.66 133.6 ± 5.13 — Relapse is based on IGA only (1)Logrank test

Number of days free of treatment was defined for each subject enrolledin period B as the time interval between a visit where IGA is assessedas 0 or 1 and the next visit. The number of treatment-free days is thesummation over all visits of period B meeting this criterion. Anadditional analysis was also performed by subtracting from the days freeof treatment any time interval between visits when the subject whilebeing IGA 0 or 1 had a major protocol deviation.

Based on IGA score showed a mean days free of treatment of 183 days forivermectin 1% QD versus 170 days for metronidazole (p=0.026). Whentaking into account the protocol deviations the mean days free oftreatment remained nearly the same 181 days versus 168 days (p=0.021) infavor of ivermectin 1% QD.

Ivermectin 1% cream QD treatment resulted in a statistically significantextended remission (i.e. delayed time to first relapse, and increase inthe number of treatment free days) of rosacea when compared toMetronidazole 0.75% BID in subjects who were successfully treated (IGA 0(clear) or 1 (almost clear)) for 16 weeks. There was also a numericaltrend in favor of Ivermectin 1% cream QD for the relapse rates (62.7%and 68.4% in the Ivermectin 1% group and Metronidazole 0.75% group,respectively). It should be noted that the differences observed in favorof Ivermectin 1% in Period B are presumably the consequence of thehigher efficacy of Ivermectin compared to Metronidazole observed at theend of Period A, with a higher proportion of subjects with an IGA=0 inthe Ivermectin group (41.6% and 29.1% in Ivermectin and Metronidazole,respectively).

The overall pharmacoeconomic benefit of Ivermectin 1% cream QD versusMetronidazole 0.75% cream BID over the one year duration of the study(Period A & B), is considerable when viewed as the sum of the followingelements: benefit of Ivermectin over Metronidazole observed at the endof Period A (84.9% of success in Ivermectin group Vs. 75.4% inMetronidazole group), time to first relapse (115 Vs. 85 days), relapserate (62.7% Vs. 68.4%) and number of days free of treatment (183.4 Vs.170.4).

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It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

We claim:
 1. A method of treating papulopustular rosacea in a subject inneed thereof, comprising topically administering, once daily, to a skinarea affected by the papulopustular rosacea a therapeutically effectiveamount of a pharmaceutical composition comprising about 1% by weightivermectin and a pharmaceutically acceptable carrier to thereby obtain asignificant reduction in inflammatory lesion count in the subject. 2.The method of claim 1, wherein as early as 2 weeks after the initialadministration of the pharmaceutical composition, the significantreduction in inflammatory lesion count is observed.
 3. The method ofclaim 1, wherein the pharmaceutical composition further comprises one ormore ingredients selected from the group consisting of: an oily phasecomprising dimethicone, cyclomethicone, isopropyl palmitate and/orisopropyl myristate, the oily phase further comprising fatty substancesselected from the group consisting of cetyl alcohol, cetostearylalcohol, stearyl alcohol, palmitostearic acid, stearic acid andself-emulsifiable wax; at least one surfactant-emulsifier selected fromthe group consisting of glyceryl/PEG100 stearate, sorbitan monostearate,sorbitan palmitate, Steareth-20, Steareth-2, Steareth-21 andCeteareth-20; a mixture of solvents and/or propenetrating agentsselected from the group consisting of propylene glycol, oleyl alcohol,phenoxyethanol and glyceryl triacetate; one or more gelling agentsselected from the group consisting of carbomers, cellulose gellingagents, xanthan gums, aluminum magnesium silicates but excludingaluminum magnesium silicate/titanium dioxide/silica, guar gums,polyacrylamides and modified starches; and water.
 4. The method of claim1, wherein the once daily topical administration to the subject thepharmaceutical composition results in more reduction in inflammatorylesion count in the subject in comparison to that achieved by topicallyadministering to the subject, twice daily, a second pharmaceuticalcomposition comprising 0.75% by weight metronidazole.
 5. The method ofclaim 1, wherein the once daily topical administration to the subjectthe pharmaceutical composition results in longer relapse-free time ofthe papulopustular rosacea in the subject in comparison to that achievedby topically administering to the subject, twice daily, a secondpharmaceutical composition comprising 0.75% by weight metronidazole. 6.A method of treating inflammatory lesions of papulopustular rosacea in asubject in need thereof, comprising topically administering, once daily,to a skin area affected by the inflammatory lesions of papulopustularrosacea a pharmaceutical composition comprising about 1% by weightivermectin and a pharmaceutically acceptable carrier to thereby obtain asignificant reduction in inflammatory lesion count in the subject. 7.The method of claim 6, wherein as early as 2 weeks after the initialadministration of the pharmaceutical composition, the significantreduction in inflammatory lesion count is observed.
 8. The method ofclaim 6, wherein the pharmaceutical composition is administered oncedaily to the skin area.
 9. The method of claim 6, wherein thepharmaceutical composition further comprises one or more ingredientsselected from the group consisting of: an oily phase comprisingdimethicone, cyclomethicone, isopropyl palmitate and/or isopropylmyristate, the oily phase further comprising fatty substances selectedfrom the group consisting of cetyl alcohol, cetostearyl alcohol, stearylalcohol, palmitostearic acid, stearic acid and self-emulsifiable wax; atleast one surfactant-emulsifier selected from the group consisting ofglyceryl/PEG100 stearate, sorbitan monostearate, sorbitan palmitate,Steareth-20, Steareth-2, Steareth-21 and Ceteareth-20; a mixture ofsolvents and/or propenetrating agents selected from the group consistingof propylene glycol, oleyl alcohol, phenoxyethanol and glyceryltriacetate; one or more gelling agents selected from the groupconsisting of carbomers, cellulose gelling agents, xanthan gums,aluminum magnesium silicates but excluding aluminum magnesiumsilicate/titanium dioxide/silica, guar gums, polyacrylamides andmodified starches; and water.
 10. The method of claim 8, wherein theonce daily topical administration to the subject the pharmaceuticalcomposition results in more reduction in inflammatory lesion count inthe subject in comparison to that achieved by topically administering tothe subject, twice daily, a second pharmaceutical composition comprising0.75% by weight metronidazole.
 11. The method of claim 8, wherein theonce daily topical administration to the subject the pharmaceuticalcomposition results in longer relapse-free time of the inflammatorylesions in the subject in comparison to that achieved by topicallyadministering to the subject, twice daily, a second pharmaceuticalcomposition comprising 0.75% by weight metronidazole.